This chapter looks at an especially interesting articulation of the posthuman within the indigenista films of Emilio “El Indio” Fernández. It identifies an attempt to modernize indigenous peasants by exposing their bodies to modern medicine. The chapter views these films in the context of Roberto Esposito’s “immunization paradigm,” a biopolitical theory that compares the medical process of immunization to the state’s role of subject creation. When a people lacks a natural immunity to a vice (improper performativity of race and gender in the case of these films), a new actor, such as the state, must step in and provide an artificial immunity. Using this theoretical framework, the chapter analyzes the films Río Escondido (1947), María Candelaria (1944), Enamorada (1946), and The Torch (1950). The readings suggest that we approach these films as allegories for a postrevolutionary society where immunological discourses prescribe appropriate gender and racial performativity for the nation.